Sleep-related breathing disorders, particularly in connection with obstructions in the region of the upper respiratory tracks, can be subjected to therapy in a physiologically well compatible fashion by increased-pressure respiration using a respiratory gas pressure, which is possibly alternating but permanently above the ambient pressure level. This increased-pressure respiration (which is generally referred to as CPAP therapy) is based on “pneumatic splinting” of the upper respiratory tracts, which is achieved by the increased pressure. That pneumatic splinting effect obviates any obstructions in the region of the upper respiratory tracts. In order to ensure that the CPAP therapy enjoys as high a level of physiological compatibility as possible, the endeavor is to reduce the respiration pressure, in particular, during an expiration phase in relation to the inspiration phase.
Hitherto favorable respiration pressure levels can either be selected by the patient himself or, for example, can also be ascertained under the charge of a doctor in the context of a stay on the part of the patient in a sleep laboratory. Investigations have shown however that both the therapy pressures desired by the patient himself and also the therapy pressures ascertained in the course of a stay in a sleep laboratory, for the inspiration pressure and also for the usually somewhat lower expiration pressure, are in part markedly above the inspiration and expiration pressure levels required for the predominant part of the sleep phase.